Headless computer entities, also known as “headless appliances” are known in the art. A known headless computer entity comprises a data-processor, memory, a plurality on input\output ports or the like, and an operating system. Headless appliances are generally designed without user interfaces, and lack a keyboard, pointing device e.g. mouse or track ball, and visual display monitor. This has the advantages both of reducing the cost of ownership, since the cost of a user interface hardware need not be borne by the purchaser, and also inhibiting interference with the operation of the appliance.
In a headless computer entity, human administrators are conventionally allowed only very limited access to the computer entity for maintenance, or in some cases no user maintenance is permitted. To safeguard against theft or loss of the computer entity involving loss of data, optionally a computer entity may have a back-up device, for example a tape back-up device such as DDS (Digital Data Storage) format back-up device. A back-up copy of an operating system of the computer entity may be made to the tape back-up device.
In a conventional computer entity where an operating system runs from a data storage device e.g. a hard disk, having re-write capability as opposed to read only memory, then there is a potential problem with backing up an operating system of the device onto a back-up medium e.g. tape, to provide for recovery of the computer entity after an operating system malfunction of “creeping corruption” of the back-up data. In particular, where an operating system fails gradually over a period of time, and back-up copies are made onto a separate back-up data storage medium, e.g. tape, periodically throughout the gradual period of operating system failure, then the operating system which is being backed up onto the back-up data storage medium is a corrupted or gradually corrupted version of the operating system Under conditions of operating system failure on the computer entity, the back-up copy of the operating system must be relied on to restore the corrupted operating system. However, if the operating system stored on the back-up medium is itself corrupted, or in a partially corrupted state immediately prior to failure, then there is no way of recovering the computer entity from an operating system failure using the back-up data storage media.
Whilst the above problem exists both for conventional computer entities having a visual display and keyboard user interface, and for headless computer entities having a user interface, the problem is less acute for conventional computer entities, because the operating system can be reloaded from an original CD ROM data carrier, using the user interface. However, for headless computer entities, because there is no user interface provided, the problem is more severe.